Antarctic Drilling Program (ANDRILL)
Date of this Version
3-8-2007
Abstract
As Antarctica’s ice teams continue to hunt for the oldest ice their drills will reach, a smaller band of rockhounds is on a similar quest to plug the gaps in the geological record. The team now has a core that promises fresh insight into how Antarctica’s ice waxed and waned over the past few million years. On December 26, 2006, a US$30-million international project called ANDRILL pulled up the final piece of a core from beneath the Ross ice shelf. Previous coring efforts have offered peeks into Antarctica’s deep history — back as far as 34 million years when the continent was first covered in ice. But the new core fills a gap in the ice shelf’s history, and sets a new Antarctic record for drilling depth. The period covered by the core — from the present to more than 5 million years ago — seems to be quite active. Preliminary analysis has revealed thick layers of a greenish rock interspersed throughout the core. This is an indication of open-water conditions, suggesting that the Ross shelf retreated and then advanced at least 50 times within the past 5 million years. With this nearly unbroken record, scientists can explore the history of the shelf in unprecedented detail.
Comments
Published in Nature 446 (March 8, 2007), pp. 129-131; doi:10.1038/446129a Copyright © 2007 Nature Publishing Group. Used by permission.